The word doom derives from a German word for an official decision, especially a judgment of punishment in a criminal case. And that’s why Doomsday is another way to refer to Judgment Day, as it’s described in the Book of Revelation in the Christian Bible. So Doomsday is both the end of the world and the time when the dead will be judged by God and be sent to heaven or hell. Trebonius compares the chaos caused by Caesar’s assassination to this nightmarish scenario portrayed in the Bible – the world seems to be coming to an end. And while Doomsday would have been a familiar, and very real, idea for Shakespeare’s audience, it’s a strange thing for Trebonius, an ancient Roman, to say. The historical Caesar died almost 50 years before the birth of Jesus.